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Liquid Hydrogen Powers a UAV For a Cool 48 Hours

Posted by Unknown on from the spy-longer dept.

An anonymous reader writes "While liquid hydrogen may not be a mainstream fuel for drones, the aerospace industry has said it holds the promise of flight endurance on the order of days, seemingly just another far-fetched aerospace industry pitch ... until now. The Naval Research Laboratory just announced that the Ion Tiger, a diminutive 37-pound airplane with a 17 foot wingspan, flew for 48 hours and 1 minute on liquid hydrogen and a fuel cell (anyone else notice the oddly specific duration? Guess it's better than 47 hours 59 minutes). This is a dramatically different scale than the liquid hydrogen powered 150 foot wingspan Boeing Phantom Eye and 175 foot wingspan AeroVironment Global Observer, which have yet to live up to their multi-day endurance projections. Interestingly enough, the well-known Global Hawk only has an endurance of 33.1 hours, which barely cracks Wikipedia's list of notable UAV endurance flights. Of course, solar-electric airplanes have flown for two weeks continuously, but that sure seems like refueling!"

6 of 72 comments (clear)

  1. Two furlongs a fortnight... by Anonymous Coward · · Score: 5, Funny

    How about you try to use units that make sense? Here's a diagram that illustrates the sillyness https://7chan.org/sci/src/132255181954.jpg

    1. Re:Two furlongs a fortnight... by maxwell+demon · · Score: 4, Funny

      Yes, they certainly should have used "172.86 kiloseconds" instead of "48 hours, 1 minute". Those odd factor-60 minutes and hours should die. It's not that hard to remember that a day is 86.4 kiloseconds and a year is about 31.5 megaseconds, after all.

      --
      The Tao of math: The numbers you can count are not the real numbers.
  2. Re:I think liquid hydrogen is dangerous as hell by maxwell+demon · · Score: 4, Funny

    That is.... Water!

    After the explosion, yes.

    --
    The Tao of math: The numbers you can count are not the real numbers.
  3. Re:There's nothing odd with 48 hours 1 minute by wonkey_monkey · · Score: 4, Insightful

    It's so no pedantic arseholes sneer about them probably rounding up.

    --
    systemd is Roko's Basilisk.
  4. Re:There's nothing odd with 48 hours 1 minute by redback · · Score: 4, Interesting

    also if you say '48 hours' it sounds like you are approximating. but 48:01 is precise enough for people to know that you are serious.

    The first man to calculate the height of mt everest calculated it to be 29,000 feet exactly. To make it sound as precise as it was, he said it was 29,002 feet.

  5. These guys aren't into marketing... by PseudoCoder · · Score: 5, Informative

    I worked with this group and I can tell you they're not into marketing, but the press people that prepared the release probably are.

    The bulk of what this NRL section does is technology demonstrators. They were also the first to air drop a drone from another drone. The odd number is probably an exact accounting of the time spent on powered flight; climb, cruise and loiter segments are the most significant for accounting for energy use during flight. Gliding and coast segments are not so interesting.

    Props to my old crew at NRL, and to the memory of Jim Kellog who developed the first prototype of what became the Ion Tiger.

    --
    "Now, I doubt any of you would prefer a rolled up newspaper as a weapon against a dictator or a criminal intruder."